The invention relates to a vehicle seat with a height-adjustable seat frame which comprises at least two seat frame parts which can move relative to one another and at least one fluid spring, in particular an air spring, arranged between the seat frame parts for height adjustment purposes, with at least one control device which is provided for influencing the fluid spring and which comprises at least one valve device with control valves which is attached to the first seat frame part and is designed to control fluid flows for the fluid spring, and also a control element which is provided on a second seat frame part and is designed to actuate the control valves, according to the preamble of claim 1.
EP 0 710 606 2 discloses a vehicle seat with a height-adjustable seat frame which is composed of two seat frame parts which can move in a scissors-like manner with respect to one another and of a seat surface arranged thereon and has a control link which is attached to one seat frame part and also a valve device with control valves which is connected to the other seat frame part and is designed to control gas flows for a fluid spring. A control device composed of this valve device with the control valves and the control link serves for adjusting the height of the scissors-type seat frame parts by means of the fluid spring, by supplying air to or discharging air from the latter. By means of an adjustment device and regardless of a relative position of the seat frame part, the control link is adjusted by a relative movement with respect to the second seat frame part such that a movement of the control link relative to the second seat frame part brought about by the adjustment device causes a height adjustment of the vehicle seat. Here, the control link is designed in the manner of a disc and is able, through its rotational movement, to operate control levers so as to actuate the control valves. The rotational movement of the control link can be carried out by means of a latching mechanism. Such latching mechanisms disadvantageously require adaptation to the switching travels of the control valves, in order to ensure a functional reliability of the height adjustment. The resulting tolerances that have to be taken into account as a result of the required adaptation could lead to an undesired premature or late switching of the control valves.
In addition, in order to carry out the normal oscillatory suspension movement without any desired height adjustment, there is a paramount need for a small throttle cross section on the control valves in order to obtain an optimised oscillatory movement of the vehicle seat in the height direction. However, when simultaneously using the control device for desired height adjustments, this leads to long lifting times of the vehicle seat, since only a small supply of air via the inlet throttle path is possible for such a desired height adjustment. Therefore, only a very slow height adjustment is possible.